Heater Necessary for GF?

I've never heated a bowl or a tank with GF ever. don't recall seeing
anyone else do it either. I thought room temp or "colder" water was
their best environment.

It does get to be a bit cold at times here in theSF Bay Area. We don't
heat the house at winter and the little fishies did fine last winter.

Any physical signs that GF are not thrilled with the water temp?

And on a side note I was curious as to why some people's GF died
(at least that is what some posts claimed) during
the east coast blackout. Why would they die so fast if the filter
stopped for 24 hours? How would that differ than from someone just
not cleaning the tank, you just would not have dirty water circulated
that's all.



Craig